Editor's note: This story is a part of a series by USA TODAY Sports called Project: June. We will publish at least one NFL-themed story every day throughout the month because fans know the league truly never sleeps.
If you follow the NFL, it's likely you've heard (or seen with your own eyes) how defenses have caught up to offenses.
It wasn't always this way. Just a short time ago, anywhere from five to seven years or so, offenses dominated the league. They morphed and shifted, and defenses were often (though not always) helpless to stop them.
That has changed. The reasons why vary and what's always been interesting is how few people have fully, and easily (that's the key), publicly explained why.
Until now.
